Vacuum insulated storage containers having improved vacuum maintenance means



Jan. 25, 1966 R. P. SKINNER 3,230,727

VACUUM INSULATED STORAGE CONTAINERS HAVING IMPROVED VACUUM MAINTENANCEMEANS Filed Jan. 27, 1964 s Sheets-Sheet 1 IN VEN TOR. 04445044AJK/N/VEB A TI'OF/VE) Jan. 25, 1966 R. P. SKINNER 3,230,727

VACUUM INSULATED STORAGE CONTAINERS HAVING IMPROVED VACUUM MAINTENANCEMEANS Filed Jan. 27, 1964 3 Sheets-Sheet 2 147 TOE/V5 y Jan. 25, 1966 R.P. SKINNER 3,230,727

VACUUM INSULATED STORAGE CONTAINERS HAVING IMPROVED VACUUM MAINTENANCEMEANS Filed Jan. 27, 1964 3 Sheets-Sheet 5 INVENTOR. KPJA/JOM P. JK/wA'TTORUE) 3,230,727 VACUUM INSULATED STORAGE CONTAINERS HAVING IMPROVEDVACUUM MAINTENANCE MEANS Ransom P. Skinner, Indianapolis, Ind.,assig'nor to Union.

Carbide Corporation, a corporation of New York Filed-Jan. 27, 1964, Ser.No. 340,317 Claims. (Cl. 62 48) This invention relates to.v'acuuminsulated'storage containers.

It has becomeucomm-on. practice to store materials at sub-ambient:temperatures in double-walled. storage. containers having insulatingmaterialsin. an evacuatedv space. It has been found that the thermal.

between the walls. conductivity of many insulating. materials used insuch containers increases sharply if even a. relatively small amount ofgas (eg. water vaporand/or air). are present.

in the evacuated space between the double walls of the container. By wayof: illustration, alumina-silica powder (a conventional insulatingmaterialused in such containers) has a thermal conductivity at 50microns of mercury pressure of approximately 0.0016 B.t.u./hr. sq. ft.F./ft.; but if a small amount of air and/or water is present to increasethe pressure to 500- microns of mercury pressure, its thermalconductivity increases to approximately-0.0054 B.t.u./h-r. sq. ft.F./ft.

It has been found that undesirable small amounts of gases in theinsulating spaces in the above-described containers cannot be removedeffectively by providing gas adsorbents in such spaces since gasadsorbents do not possess adequate gas adsorbent properties at thetemperatures (e.g. from --40 F. to +60 F.) often prevailing in suchspaces.

It is an object of this invention to provide means for maintaining thevacuum in evacuated insulated spaces of double walled storage containersin which materials are stored at temperatures from 40 F. to +60 F.

Other objects and advantages of this invention will be apparent from theensuing enclosure and the appended claims.

In the drawings,

FIGURE 1 is a front elevation view in section of an insulated containerof this invention wherein a conduit joins the evacuated space of adouble-walled storage compartment and the evacuated space of adouble-walled cryogenic liquid container.

FIGURE 2 is a longitudinal view, partly in section, of an insulatedcontainer of this invention wherein a common outer wall houses both astorage compartment and a cryogenic liquid container.

FIGURE 3 is a sectional view of a fastening member employed in theembodiment of FIGURE 2 to fasten the storage compartment to the outerwall and to define an access conduit.

FIGURE 4 is a schematic diagram of conduit system which can be employedin conjunction with the embodiment of FIGURE 2.

FIGURE 5 is a front elevation view in section of an insulated containerof this invention wherein a storage compartment and a cryogenic liquidcontainer have separate evacuable insulating spaces.

The invention is based, in part, on the discovery that a vacuum can bemaintained in the evacuated insulated space of a double-walled storagecontainer used for storing materials at temperatures from about -40 F.

. to +60 F. by providing a mass of a gas adsorbent that is cooled tocryogenic temperatures (e.g. temperatures below 320 F.) and that is ingaseous communication with the evacuated space. The improved gasadsorption capacity of the gas absorbent at cryogenic temperatures "iceallows for the ready adsorption of any small amountof gas in theevacuated space. Accordingly, this invention provides an insulatedcontainer for storing materials at a temperature from 40 F. to +60 F.,said container comprising (a) a double walled storage compartment havingan outer shell and an inner shell, said inner shell defining a space forstoring said materials and said outer and inner shells defining anintervening evacuable space therebetweenj (b) a separate receptacle"which is spaced from the storage compartment and which contains a gasadsorbent that has a greater gas-adsorption capacity at temperaturesbelow about l 5 0 F. than at about ambient temperatures, that is cooledto a tern;

perature below about F. and that is sealed from the atmosphere; and (c)gas-communication means pro viding gaseous communication between the.evacuable;

space and the gas adsorbent so, that the gas adsorbent can mainta n avacuum in the evacu-able'space.

The space is initially evacuated to. the desired low, pressure by anysuitable means (e.g. mechanical pumps can be used to lower the pressureto a pressure slightly. above the desired pressure and then theadsorbent can be used. to further lower the pressure in the space. tothe desired pressure). There-after, any gas entering the evacuated spaceis adsorbed by the adsorbent which thereby main;- tains the desiredvacuum in the space.

One more specific embodiment of this invention pro.- vides an insulatedcontainer comprising (1) a doublewalled storage compartment and (2) adouble-walled cryogenic liquid container. associated therewith. Thestorage compartment has an outer shell and: an inner. shell defining anintervening first evacuab'le space there between, a storage space withinthe inner shell, insulation in the first evacuable space for insulatingvthe storage space and access means for introducing materials to bestored into the storage space and for withdrawing said materials fromthe storage space. The double-walled cryogenic liquid container hasouter and; inner walls defining an intervening second evacuable spacetherebe tween that is in gaseous communication with the first evaouablespace, a cryogenic liquid storage space within the inner wall,insulation in the second evacuable' space for insulating the cryogenicliquid storage space, access" means for introducing a cryogenic. liquidinto the cryogenie liquid storage space and a-mass of; a gas adsorbentwhose gas absorbing properties are better at cryogenic temperatures thanat ambient temperatures disposedin the second evacuable space. Theadsorbent is in thermal contact with a cryogenic liquid introduced intoand main' tained in the cryogenic liquid storage space and theadsorbentis in gaseous communication with boththe first and second evaeuab'lespaces for maintaining a vacuum in each space after they have beenevacuated.

In general, any gas adsorbent whose gas adsorption properties are betterat cryogenic temperatures than at about ambient temperatures can beemployed in the insulated containers of this invention. Thus, theadsorbent can be a material such as charcoal (preferably coconutcharcoal) or silica gel. However, it is preferred thatflth'e adsorbentbe a crystalline zeolitic molecular sieve. Suitable zeolitic molecularsieves include both the naturally: occurring zeoliticmolecular sievesand the synthetic. ze0= litic molecular sieves. Among thenaturally-occurring zeolitic molecular sieves are chabazite, erionite,mordenite and faujasite, these being adequately described in thechemical art. Synthetic zeolitic molecular sieves include zeolites Thecooling of the adsorbent is readily accomplished with A, D, L, R, S, T,X and Y, as Well as the mordenite-type material known commercially asZeolon and described in Chemical and Engineering News, March 12, 1956,pages 5254.

The pore size of the zeolitic molecular sieves may be varied byemploying different metal cations. For example, sodium zeolite A has apore size of about 4 angstrom units whereas when calcium cations havebeen exchanged for at least about 40 percent of the sodium cationscalcium zeolite A has a pore size of about angstrom units.

Zeolite A is a crystalline zeolitic molecular sieve which may berepresented by the formula:

wherein M represents a metal, n is the valence of M and y may have anyvalue up to about 6. The as-synthesized Zeolite A contains primarilysodium ions and is designated sodium zeolite A, described in more detailin U.S. Patent No. 2,882,243, issued April 14, 1959.

Zeolite X is a synthetic crystalline zeolitic molecular sieve which maybe represented by the formula:

wherein M represents a metal, particularly alkali and alkaline earthmetals, n is the valence of M and y may have any value up to about 8,depending on the identity of M and the degree of hydration of thecrystalline Zeolite. Sodium zeolite X has an apparent pore size of aboutangstrom units. vZeolite X, its X-ray diifraction pattern, itsproperties and methods for its preparation are described in detail inU.S. Patent No..2,882,244, issued April 14, 1959.

Zeolite Y is described and claimed in U.S. Patent application Serial No.109,487, filed May 12, 1961, now Patent No. 3,130,007, in the name of D.W. Breck and issued as U.S. Patent N0. 3,130,007 on April 21, 1964.

Agglomerates comprising both zeolitic molecular sieves and finelydivided metal particles can also be employed as the gas adsorbent in thecontainers of this invention. More specifically, such agglomeratescomprise zeolitic molecular sieve crystals of less than 10 micronsindividual size and metal bodies having at least one dimension less than50 microns, the ratio of the metal body size to the zeolitic molecularsieve crystal size being at least 5 to 1. The metal bodies are uniformlydispersed throughout the agglomerate in quantity sufiicient toconstitute between about -5 and 30 percent by weight of the agglomerateand are sintered to the outer surface of the molecular sieve crystals.The metal should have a melting point over 300'C."and is employedprimarily as a structural component in the multi-crystalline agglomeratebut probably also enters into the formation of a chemical bond with themolecular sieve crystals by virtue of the sintering. Among the metalssuitable for use in the multicrystalline agglomerate are those of groupsIb, IIb, IIIa, Va, Vb, VIb, VIIv and VII of the Periodic Table (Handbookof Chemistry and Physics, thirty-eighth edition, page 394, ChemicalRubber Publishing Co., 1956). Silicon, germanium, lead and tellurium arealso suitable. Exemplary metals-include, but are not limited to, copper,silver and gold of group Ib, magnesium of group Ila, zinc of group IIb,boron and aluminum of group IIIa, yttrium of group IIIb, antimony ofgroup Va, Vanadium of group Vb, chromimum of group VIb, manganese ofgroup VHb and iron, nickel, platinum and palladium of group VIII.Mixtures and alloys of these metals may also be employed. Suchagglomerates are disclosed and claimed in U.S. Patent application SerialNo. 300,163, filed August 6, 1963.'

The amount of gas adsorbent employed in the insulated containers of thisinvention will depend on such factors as the particular cryogenic liquidand adsorbent used, the amount of gas to be adsorbed, the size of thevacuum 4 space, the length of time that the vacuum is to be maintainedand the like.

The gas adsorbents employed in the insulated containers of thisinvention are in thermal contact with a cryogenic fluid when thecontainer is in use. Suitable cryogenic fluids include inert liquidshaving boiling points at atmospheric pressure below -320 F. Such liquidsinclude liquid nitrogen, liquid oxygen and the like. As used herein, theterms liquefied gas and liquefied refrigerant gas are used as synonymsfor the term cryogenic liquid. Cold gaseous nitrogen is also useful.

Any suitable insulating material can be used to insulate the cryogenicliquidcontainer and the storage compartment in the insulated containersof this invention. Thus, the cryogenic liquid container can be insulatedwith composite insulating materials such as those composed of alternatelayers of thin metallic sheets (e.g. aluminum foil) and glass fibersheets (e.g. in the form of paper or;

webbing). Suitable composite insulating materials are disclosed in U.S.Patents 3,007,596, 3,018,016, 3,007,576, 3,009,600 and 3,009,602. Thestorage compartment can be insulated with the latter-mentioned compositeinsulating materials or with polyurethane foam. I

Referring now more specifically to the drawings, FIG- URE 1 shows aninsulated container of the presentinvention composed of cryogenic liquidcontainer 2 and storage compartment 3. The walls 4 and 5 of cryogenicliquid container 2 are spaced apart so as to define an interveningevacuable space 6. Similarly, the outer shell 7 and inner shell 8 of thestorage compartment 3 are spaced apart so as to define interveningevacuable space 9. Evacuable spaces 6 and 9 are, in a preferredembodiment of this invention, in gaseous communication throughdouble-walled insulated conduit 10. However, it is not essential thatconduit 10 be a double-walled, insulated connecting means. Cryogenicliquid container 2 contains a cryogenic liquid 11 (e.g. liquid nitrogen)which is in thermal contact with adsorbent 12 that is retained in theperforated metal blister 13 welded or otherwise attached to wall 5. Theperforations in metal blister 13. provide gaseous communication amongthe adsorbent 12, evacuable space 6 and (through conduit 10) evacuablespace 9. Cryogenic liquid container 2 is provided with an accessmeans(not shown) for introducing the cryogenic liquid therein. Similarly, thestorage compartment 3 is provided withan access means (not shown) forintroducing materials to be stored therein and for removing suchmaterials. Walls 5 and 6 are composed of aluminum or other suitablematerial and outer shell 7 and inner shell 8 are composed of stainlesssteel or other suitable materiaL. Insulating materials 12 are providedin the evacuable spaces around inner walls 5, the inner wall of conduit10 and inner shell 8.

FIGURE 2 depicts an insulated container of this invention having anouter shell 50 within which are located two separate compartments,liquefied gas storage compartment 51 and perishable food storagecompartment 52. Outer shell 50 and compartments 51 and 52 can becomposed of any suitable material such as stainless steel or aluminum.

The outer surfaces of liquefied gas storage compartment 51 andperishable food storage compartment 52 together with the inner surfaceof outer shell 50 define an intervening evacuable space 53. Evacuablespace 53 also extends between the adjacent walls of liquefied gasstorage compartment 51 and perishable food storage compartment 52.Accordingly, both compartmentfil and compartment 52 are surrounded bycommon evacuable space 53. A plurality of solid cylindricalload-supporting pegs'54 or other load-supporting means are disposed inevacuable space 53 between the liquefied gas storage compartment 51 andthe adjacent portion of the outer shell 50 so as to support theatmospheric load on the outer shell. Suitable loadsupport means aredescribed and claimed in U.S. Patent Application Serial No. 340,311,filed January 27, 1964, in the names of W. L. Berner, C. P. Mulcahey andR. P. Skinner, entitled Load Support Means for Thermally In;

sulated Container. Those pegs that are disposed between the, bottomsurfaces of the compartments 51 and 52 and the outer shell 50 so as toalso support the weight of compartments 51 and 52. Additionally, pegs 54are disposed between liquefied gas storage compartment 51 and perishablefood storage compartment 52 in order to maintain these compartments at adistance from each other equal to the length of the pegs so as tostabilize the compartments against relative movement and prevent thermalcontact between the walls of the compartments. Compression-sensitiveinsulating material 55 (e.g. insulation such as is described in theabove-mentioned United States patents) is disposed in the evacuablespace 53 around compartments 51 and 52 so as to minimize the heat leakfrom outside the outer shell 50 into the compartments 51 and 52 and tominimize heat leak from perishable food storage compartment 52 toliquefied gas storage compartment 51. Inasmuch as the temperaturedifference between a liquefied gas storage compartment 51 and thesurfaces surrounding it is much greater than the temperature differencebetween perishable food storage compartment 52 and the surfacessurrounding it, the thickness of the insulating material 55 aroundliquefied gas storage compartment 51 may be as shown in FIGURE 2,greater than the thick-.

ness of insulating material 55 around perishable food storagecompartment 52. Insulating material 55 is provided with holes throughwhich pass pegs 54. A liquefied refrigerant gas 5511 (such as liquidnitrogen) is provided in liquefied gas storage compartment 51 and thisliquefied gas 55a is in thermal communication with a mass of a zeoliticmolecular sieve gas adsorbent 56 which is retained in a perforated metalblister 57 depending from the bottom of liquefied gas storagecompartment 51. The liquefied gas 55 cools the molecular sieve 56thereby improving the gas adsorbing properties of the sieve. Theperforations in the blister 57 provides gaseous communication betweenthe zeolitic molecular sieve gas adsorbent 56 and evacuable space 53 andserves to maintain a vacuum in the evacuable space after the evacuablespace is evacuated; Strips of gas-impervious organic polymer 58 havinglow thermal conductivity join the top, bottom and side walls ofperishable food storage compartment 52 to outer wall 50. These strips oforganic polymer 58 serve to prevent the passage of gas into evacuablespace 53 and serve to prevent heat leak into perishable food storagecompartment 52 while at the same time defining an access conduit forintroducingfood into perishable food storage compartment 52. Insulatedstorage compartment door 59 provides access'to perishable food storagecompartment 52. Door 59 can be insulated with polyurethane foam or othersuitable insulating material. Alternately, the desired degree ofinsulating can be achieved by using a vacuum panel door. The floor ofperishable food storage compartment 52 is provided with cover plate 60rotatable about hinge 61 which can be positioned over the strip oforganic polymer 58 connecting the floor of compartment 52 to outer shell50. Cover plate 60 prevents damage to the strip of .organic polymer 58when perishable food is being introduced into perishable food storagecompartment 52. In order to minimize heat leak into compartment 52through cover plate 60, cover plate 60 is charged so thatit can berotated into the position shown in FIG- URE 2 when not needed to protectlower strip of organic polymer 58. Low heat conducting filling tube 63is provided for introducing liquefied gas 55a into liquefied gas storagecompartment 51 and transfer conduit 64 is provided for transportingliquefied gas 55a from liquefied gas storage compartment 51 toperishable food storage compartment 62 in order to provide refrigerationfor perishable food stored in perishable food storage compartment 52.Perforations are provided in the portion of the transfer conduit 64located within perishable food storage compartment 52 to allow theliquefied gas 55 to be sprayed from the transfer conduit 64 as a finemist on the perishable food within perishable food storage compartment52.

Suitable means are provided for regulating the fiow of liquefied gas 55ainto perishable food storage, compartment 52 so as to maintain theperishable food at a predetermined desired temperature. The temperaturein compartment 52 will be dependent on thetype material being stored(e.g. fruit, meat, vegetables etc.) and will usually be between 40 F.and +60 F. Such flow-regulating means include the feature ofdiscontinuing the transfer of the liquefied gas into perishable foodstorage compartment 52 when insulated storage compartment door 59 isopened. This latter feature prevents a waste of the liquefied gas whenthe insulated storage compartment door 59 is opened to introduceperishable food into perishable food storage compartment 52 or towithdraw the food.

The pressure required to transfer the liquefied gas 55a from liquefiedgas storage compartment 51 through transfer conduit 54 in whichperishable food storage compartment 52 can be created in any convenientmanner. Thus, the pressure can be created by a heating coil in thebottom of liquefied storage compartment 51 which creates the desiredpressure by vaporizing a portion of the liquelied gas 55a in response toa temperature sensing element in perishable food storage compartment 52.Preferably, the pressure is created initially by charging the liquefiedgas to the liquefied gas storage compartment 51 along with vapor of thegas at a pressure sufficient to insure. the transfer of the gas duringthe desired period of .operation. Preferably, a pressure from 5 p.s.i.g.to 25 p.s.i.g. is maintained in compartment 51.

Liquefied gas storage compartment 51 is preferably provided withinternal bracing means or supports to assist in carrying loads imposedon compartment 51.

It is desirable to provide for the expansion and contraction of theouter shell 50 and-the perishable food storage compartment 52 of theinsulated container of FIGURE 2. The expansion and contraction of the.outer shell 50 is readily provided for by employing corrugated walls asillustrated by corrugated wall 50a in FIGURE 4. The expansion andcontraction of perishable food storage compartment 52 can be providedfor by constructing wall 65 of relativelythin and resilient material sothat it will tend to buckle under stress (e.g. a 7.5 ft. x 7.5 ft. wallcan be made 0.100 inch thick for this purpose Alternately, the expansionand contraction of perishable food storage compartment 52 can beprovided for by employing an elastic material also possessing lowthermal'conductivity and gasimpervious properties as organic polymerstrip 58. In the latter case, wall65 ca nbe made thicker and, therefore,more rigid (e.g. a 7.5 ft. x 7.5 ft. wall can be made 0.50 inch thickfor this purpose). Organic polymer strips suitable for this use includethose composed of butyl rubber.

The manner in which the strips of organic polymer 58 can be attached tothe walls of perishable food storage compartment 52 and outer shell 50is illustrated by FIG- URE 3. In FIGURE 3, the strip of organic polymer58 is provided with enlarged end portions 58a which are adapted to fitinto bracket 52a attached to the floor of inner compartment 52 and intobracket 50a attached to outer shell 50. Enlarged end portions 58a oforganic polymer strip 58 are maintained in brackets 52a and 50a b-yplates 52b and 50b held in place by means of screws 52c and 500.

FIGURE 4 illustrates a conduit arrangement suitable for use intransferring a cryogenic liquid from storage compartment 51 of FIGURE 2to storage compartment 52 of FIGURE 2 in order to refrigerate thecontents of compartment 52 of FIGURE 2. Compartment 51 is filled with 'acryogenic liquid through conduit 63 and then the interior of compartment51 is pressurized by conventional means to a pressure of about 5p.s.i.g. to 25 p.s.i.g. Conduit 64 is provided with a solenoid valve 64awhich is connected to a suitable temperature controller (not shown).Conduit 66 is provided With a relief valve and safety valve (not shown).When the temperature in compartment 52 arises above a predeterminedpoint, the controller energizes a solenoid 64a to open it. The cryogenicliquid then flows from compartment 51 into compartment 52 throughconduit 64 because of the pressure differential (compartment 52 is atabout atmospheric pressure). The cryogenic liquid is sprayed intocompartment 52 through perforations in conduit 64 until the temperaturein compartment 52 decreases to the predetermined point. At the latterpoint, solenoid valve 64a closes, terminating the flow of the cryogenicliquid.

The following description illustrates another form of the insulatedcontainers of this invention. The container consisted of (1) a standardcommercially available double-walled dewar used for storing liquidnitrogen and (2) a storage compartment. The storage compartment wassimilar to-the storage compartment 3 of FIGURE 1. The storagecompartment had a storage capacity of 39,300 cubic inches and theevacuable space in the storage compartment was one inch wide. Theevacuable space in the storage compartment was evacuated to about onemicron of mercury pressure employing conventional pumping means.compartment was maintained at about -10" F. by purging the interior ofthe compartment with liquid nitrogen. Ten liters of liquid nitrogen weremaintained in the dewar. Five pounds of zeolite A were placed in anair-tight aluminum can which was air-tightly fitted with a plastic hose.The can was inserted in the dewar so that it was immersed in the liquidnitrogen and the hose extended out of the top of the dewar through thenecktube of the dewar. The hose was air-tightly attached to an openingin the outer shell ofthe storage compartment so as to provide gaseouscommunication between the liquid nitrogen-cooled zeolite A and theevacuable space of the storage compartment. A vacuum of about one micronof mercury pressure was maintained in the evacuable space of the storagecompartment for one year in this manner. During this period, the liquidnitrogenin the dewar was replenished at a rate of about 10 liters ofliquid-nitrogen per day. The above-described. container is illustrativeof a container of this invention WhBI'ClIl-thfi adsorbent used tomaintain a vacuum in the evacuable space in the storage compartment isnot also used to maintain a vacuum in the evacuable space in thecryogenic liquid container and wherein the evacuable space of thecontainer is not in gaseous communication with the evacuable space ofthe dewar. This container is depicted byFIG- URE 5 wherein storagecompartment 1 has stainless steel or aluminum Walls 2 and 3 spaced apartto define intervening evacuable insulating space 4. Space 4 is ingaseous communication with a mass of adsorbent 5 (Zeolite A) throughplastic conduit 6. Adsorbent 5 is retained in air-tight aluminum can 7which is immersed in liquid nitrogen 8 that is in dewar 9. Compartment 1is provided with low heat conducting plug 10 through which passthermistor lead 11 and liquid nitrogen conduit 12 that communicates witha liquid nitrogen reservoir (not shown). When the temperature in storagespace 14 rises above a predetermined temperature, thermistor 13activates a valve (not shown) in conduit 12 permitting liquid nitrogento pass through conduit 12 and purge storage space 14 till thetemperature therein falls to another predetermined temperature at whichpoint the valve is closed. Conduit 6 has pinch-off tube 18 for use inevacuating the conduit, can 7 and space 4. Stainless.

steel inner shell 15 and stainless steel outer shell 16 of dewar 9define another intervening evacuable insulating space 17.

The storage compartments in the containers of this The temperaturewithinvthe storage 8 invention are useful for storing meat, fish, fowl,vegetables, fruits and the like.-

What is claimed is:

1. An insulated container for storing materials at a temperature from.40 F. to +60 F., said container comprising (a) a double-walled storagecompartment having an outer shell and an inner shell, said inner shelldefining a space for storing said materials and said outer and innershells defining an intervening evacuable space therebetween; (b) aseparate receptacle which is spaced from the storage compartment andwhich contains a gas adsorbent that has a greater gas-adsorptioncapacity at temperatures .below about 150 F. than at about ambienttemperatures, that is cooled to a temperature below about 150 F. andthat is sealed from the atmosphere; and (c) gas-communication meansproviding gaseous communication between the evacuable space and the gasadsorbent so that the gas adsorbent can maintain a vacuum in theevacuable space.

2. An insulated container comprising (1) a storage compartment forstoring materials at a temperature from about 40 F. to about +60 F.,said compartment having (a) an outer shell and an inner shell definingan intervening first evacuable space therebetween, said inner shelldefining a storage space for storing said materials, a storage spacewithin the inner shell, (b) thermal insulating material in the firstevacuable space for insulating the storage space. and (c) access'meansfor introducing materials to be stored into said storage space and forwithdrawing said material from the storage space and (2) a separatedouble-walled cryogenic liquid container which is spaced from thecompartment and which has (a) outer and inner Walls defining anintervening second evacuable space therebetween that is in gaseouscommunication with'the first evacuable space, said inner walls defininga storage space for a' cryogenic liquid, (b) thermal insulating materialin thesecond evacuable space for insulating the cryogenic liquid storagespace, (c) access means for introducing a cryogenic liquid into thecryogenic liquid storage space and (d) a mass of a gas adsorbent whosegas adsorption capacity is greater at temperatures below about 150 F.than at about am bient temperatures disposed in the second evacuablespace,

, said adsorbent being in thermal contact with a cryogenic liquid in thecryogenic liquid storage space and said adsorbent being in gaseouscommunication with both the first and second. evacuable spaces formaintaining a vacuum in each space after evacuation thereof.

3. The container of claim 2 having means for withdrawing a portion ofthe cryogenic liquid from cryogenic liquid storage space for coolingmaterials stored in the storage space of the storage compartment.

4. The container of claim 2Wherein the outer shell of the storagecompartment is corrugated.

5. The container of claim 1 wherein theadsorbent is a crystallinezeolitic molecular sieve.

References Cited by the Examiner UNITED. STATES PATENTS ROBERT A.OLEARY, Primary Examiner.

LLOYD L. KING, Examiner.

1. AN INSULATED CONTAINER FOR STORING MATERIALS AT A TEMPERATURE FROM-40*F. TO +60*F., SAID CONTAINER COMPRISING (A) A DOUBLE-WALLED STORAGECOMPARTMENT HAVING AN OUTER SHELL AND AN INNER SHELL, SAID INNER SHELLDEFINING A SPACE FOR STORING SAID MATERIALS AND SAID OUTER AND INNERSHELLS DEFINING AN INTERVENING EVACUABLE SPACE THEREBETWEEN; (B) ASEPARATE RECEPTACLE WHICH IS SPACED FROM THE STORAGE COMPARTMENT ANDWHICH CONTAINS A GAS ADSORBENT THAT HAS A GREATER GAS-ADSORPTIONCAPACITY AT TEMPERATURES BELOW ABOUT -150*F. THAN AT ABOUT